Cycloadditions of Allylsilanes, Part 11. Stereoselective Synthesis of Hydroxycyclopentanes and Hydroxymethylcyclobutanes by Titanium Tetrachloride-Promoted [3+2] and [2+2] Cycloadditions of Sterically Hindered Allylsilanes and Subsequent Oxidative Cleavage of the Carbon-Silicon Bond

Even highly sterically hindered organosilicon compounds containing the bulky tert-butyldiphenylsilyl group can be oxidatively cleaved to the corresponding carbinols using a modified protocol of the original Fleming-Tamao oxidation that generates the intermediate tert-butyldifluorosilyl derivatives. This novel application emphasizes the utility of allyl-tert-butyldiphenylsilane as a building block for the stereoselective synthesis of either hydroxycyclopentanes or hydroxymethylcyclobutanes via the sequence titanium tetrachloride-promoted cycloaddition and oxidative cleavage.

allylsilanes - titanium tetrachloride - cycloadditions - oxidative cleavage - tert-butyldiphenylsilyl derivatives